Digital Commons Network^™

A Comparative Analysis Of Pediatric And General Hospital Nurse Recruitment Practices, Rebecca Parsons Scott

Community & Environmental Health Theses & Dissertations

The focus of this study is a comparison of the National Association of Health Care Recruiter's annual recruitment survey with a duplicate survey that was sent to pediatriconly acute care hospitals. The goal was to determine differences between the recruitment and retention statistics found in all hospitals compared to those found in pediatriconly hospitals. Also, a major consideration was to find correlations among the variables in nurse recruitment and retention that might lead to a better understanding of what influences the recruitment budgeting process and how recruitment dollars might be spent most efficiently.

There was no significant difference found between …

The Effects Of Two Polycyclic Aromatic Hydrocarbons Benzo[A]Pyrene And Naphthalene On Reproductive Success Embryological Development Larval Physiology And Mortality Of The Mud Crab Rhithropanopeus Harisii (Gould), Gregory V. White

OES Theses and Dissertations

Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap) and benzo[a]pyrene (B[a]P) are common in the water column and sediments of estuarine and coastal areas. The mud crab Rhithropanopeus harrisii was exposed to varying concentrations of Nap or B[a]P to determine the effects on reproductive success, embryological development, larval physiology and mortality. Nap and B[a]P decreased hatching success and prolonged embryological development. Both pollutants produced high abnormality frequencies for egg exposed larvae. Molt frequency and respiratory rates of larvae from non-exposed eggs were more chronically affected by these pollutants than were egg exposed larvae. The EC₅₀ concentrations were determined for …

A Software Design Tool For Predictable Performance In Real-Time, Data Flow Architectures, Brij Mohan V. Mandala

Electrical & Computer Engineering Theses & Dissertations

A software design tool which aids in the performance evaluation and selection of operating points for an algorithm implemented in ATAMM defined data flow architectures is presented in this thesis. ATAMM (Algorithm To Architecture Mapping Model) is a new graph theoretic model developed by researchers at Old Dominion University and the NASA-Langley Research Center. ATAMM is capable of modeling the execution of large-grained algorithms on distributed data flow architectures. A software tool is required for predicting the performance, determining the resource requirements and for selecting suitable operating points for an ATAMM based system. The ATAMM Design Tool presented in this …

Measurement Of Thermal Noise In Condenser Microphones In A Vacuum-Isolation Vessel, Kim Chi Thi Ngo

Electrical & Computer Engineering Theses & Dissertations

The electrical noise generated by thermal agitation of the air molecules impinging upon the membrane of a condenser microphone and from its associated preamplifier has been studied analytically and experimentally over a wide bandwidth. These background noise levels constitute one of the most important specifications of a microphone for they determine the lowest sound pressure that can be detected. Therefore, a new method for measuring the thermal agitation noise within a bandwidth of 1-25600 Hz has been developed. The theoretical and experimental measurements of thermal agitation noise in a condenser microphone by enclosing the microphone in a vessel which is …

Optical And High Electric Field Effects In Bulk Gallium Arsenide Switches, Randy Roush

Electrical & Computer Engineering Theses & Dissertations

During the past few years, bulk, photoconductive switching has become recognized as a viable topic for future research on moderate and high power switches. The two-pulse, or BOSS, concept relies on an excitation laser pulse, and a separate de-excitation pulse in conjunction with silicon doped, copper compensated, GaAs to create a variable temporal electrical pulse width. The research contained in this document provides information concerning the feasibility of the BOSS concept, as the switch is scaled to larger sizes, and higher voltage and current. The major concern will be the high voltage and current effects. The absorption length for 1064 …

Interaction Between Amphetamine And Ethanol On Amphetamine-Produced Conditioned Place Preference, Cheryl Pelphrey-Weigand

Psychology Theses & Dissertations

Male Long-Evans rats were conditioned 6 days, alternating drug and non-drug conditions, using injections of .6 mg/kg d-amphetamine, amphetamine plus 60mg/kg ethanol, or amphetamine plus 120 mg/kg ethanol. These injections were given in a specific side of the shuttlebox to assess the development of a place preference or aversion. The amount of time spent in the drug-paired side was analyzed on 2 non-drugged test days. Rats spent significantly more time in the drug-paired side on Test Day 1 than on Test Day 2. When the ethanol groups were combined, these rats spent significantly more time in the drug-paired side than …

The Modeling Of The Interactions Of Pellets With Magnetic Fusion Plasmas For Alpha Particle Diagnostics, Abdel-Ghafar Mahmood El-Cashlan

Electrical & Computer Engineering Theses & Dissertations

A model for the interactions of hydrogen and carbon pellets with thermonuclear fusion plasmas has been developed and solved to determine the charge-state spatial distributions in the ablation cloud surrounding the pellet. The ionization is treated in a self-consistent manner in the energy balance and the collisional radiative (CR) model is used to calculate the ionization levels. External plasma electron effects on ionization are included. The electron heat flux is modeled as a multigroup distribution. The channelling of the flow along the field line is treated phenomenologically by restricting the cross-sectional area of the flow. The predictions of the model …

Hydrogeology And Water Budget Analysis Of Two Interdunal Ponds Nags Head Woods Ecological Preserve, Dare County, North Carolina, Richard A. Hisert

OES Theses and Dissertations

Ground-water-fed interdunal ponds in Nags Head Woods Ecological Preserve lose as much as 7600 m³ yr^-1 of water through evaporation. This withdrawal of groundwater is sufficient to significantly alter flow patterns through the surficial aquifer on Bodie Island, N.C. Statistical analyses of evaporation estimates derived by various methods indicate a weak correlation, (r²=0.4-0.5) between pan evaporation data from Aurora, N.C. and pond evaporation at Nags Head Woods calculated by water budget analyses.

Results of stratigraphic and pedologic analyses in and around the ponds indicate that the ponds formed after development of multiple generations of dunes. This …

Deep Level Characterization Studies In Gaas, Gordhan R. Barevadia

Electrical & Computer Engineering Theses & Dissertations

The goal of this research was to investigate deep levels in different types of GaAs, a material for high power optically controlled bulk semiconductor switches. For low resistivity semiconductors, such as silicon doped GaAs material (p =0.054 Ω cm), deep level transient spectroscopy (DLTS) was used to characterize deep levels. Three deep levels (EL6, EL3, and EL2) have been detected in this material. For high resistivity semiconductors (p > 10⁴ Ω cm), difficulty of electrical carrier injection and of making a junction does not permit the use of DLTS technique. Therefore, an experimental set-up of the photo-induced current transient spectroscopy …

Effects Of Applied Soil Repellent Finish On Pesticide Residues In Work Clothing, Sandra L. Prior

Community & Environmental Health Theses & Dissertations

This study explores the feasibility of using an applied soil repellent finish, Scotchgard, on 100% cotton denim fabric in order to enhance the removal of atrazine and alachlor residue during the laundering process. The experimental findings provided no statistically significant evidence that Scotchgard fabric protector reduced pesticide residuals on the 100% cotton denim fabric either before or after laundering. A significant finding secondary to the study involved the possible interaction of Scotchgard with the pesticide alachlor, leaving greater amounts of residual on the fabric after laundering than those found with no fabric treatment. This suggests that agricultural workers be cautioned …

Effects Of Quantum Noise On A Two-Level System In A Single-Mode Cavity, Linda L. Vahala

Electrical & Computer Engineering Faculty Publications

The effects of quantum noise on a two-level system in the bad-cavity regime are considered perturbatively in the form of closure at the pair-correlation level. It is found that pair-correlation effects can reduce the level of semiclassical chaos. However, under the rotating-wave approximation (RWA), quantum noise can lead to chaos if there is an initial population inversion, while the full RWA Hamiltonian system remains integrable.

The Relationships Of Body-Image Attitudes To Sexual Functioning And Experiences In A Normal College Population, Jill D. Hangen

Psychology Theses & Dissertations

This study examined the relationships of body-image attitudes and sexual attitudes, experiences, and functioning in a college population. Sixty-five males and 120 females completed a variety of established self-report measures assessing the constructs under study, as well as two new measures developed in this study. The new measures included (1) The Sexual Experiences and Problems Survey for self-assessment of difficulties in sexual functioning, and (2) The Body Exposure in Sexual Activities Questionnaire to measure self-consciousness and avoidance of body exposure in sexual contexts. Analyses were performed in the data of those predominantly heterosexual subjects who reported a history of sexual …

The Hydrogeology And Leachate Generation Of An Alum Sludge Lagoon Chesapeake Virginia, Charles M. Darling

OES Theses and Dissertations

In 1986 the City of Chesapeake, Virginia began to dig shallow ponds ("lagoons") to contain alum sludge, a waste generated by the City from the process of treating potable water. Borings at the disposal site reveal that the near-surface geologic units include a thin mud-rich facies which overlies a thick sandy facies, both of which are in the Lynnhaven Member of the Tabb Formation. At 7 meters depth, a clay-rich facies of the Yorktown Formation (Morgarts Beach Member?) underlies the sandy water table aquifer. Water levels from twenty observation wells and two monitoring wells installed into the water table aquifer …

A Comparative Study Of Spectral Peaks Versus Global Spectral Shape As Invariant Acoustic Cues For Vowels, Amir Jalali Jagharghi

Electrical & Computer Engineering Theses & Dissertations

The primary objective of this study was to compare two sets of vowel spectral features, formants and global spectral shape parameters, as invariant acoustic cues to vowel identity. Both automatic vowel recognition experiments and perceptual experiments were performed to evaluate these two feature sets. First, these features were compared using the static spectrum sampled in the middle of each steady-state vowel versus features based on dynamic spectra. Second, the role of dynamic and contextual information was investigated in terms of improvements in automatic vowel classification rates. Third, several speaker normalizing methods were examined for each of the feature sets. Finally, …

A Mathematical Model Of The Dynamics Of An Optically Pumped Codoped Solid State Laser System, Thomas G. Wangler

Mathematics & Statistics Theses & Dissertations

This is a study of a mathematical model for the dynamics of an optically pumped codoped solid state laser system. The model comprises five first order, nonlinear, coupled, ordinary differential equations which describe the temporal evolution of the dopant electron populations in the laser crystal as well as the photon density in the laser cavity. The analysis of the model is conducted in three parts.

First, a detailed explanation of the modeling process is given and the full set of rate equations is obtained. The model is then simplified and certain qualitative properties of the solution are obtained.

In the …

An Artificial Neural Approach To The Decomposition Problem, Chandrashekar L. Masti

Electrical & Computer Engineering Theses & Dissertations

The goal of this thesis is to develop an artificial neural approach toward addressing the intractability involved with the decomposition problem. The search for the lattice of substitution property (s. p.) partitions essential to decompositions is cast into the framework of constraint satisfaction. An artificial neural network is developed to provide solutions by performing optimization of a mathematically derived objective function over the problem space. The issue of transitivity is verified to belong to a class of problems beyond the scope of solvability for conventional quadratic-order constraint satisfaction neural networks. A theorem is stated and proved establishing that third-order correlations …

Evidence Of A Neurogenic Component During Ige-Mediated Inflammation In Murine Skin, Victoria Jean Cavanaugh

Biological Sciences Theses & Dissertations

The direct stimulation of sensory nerves or the intradermal injection of neuropeptides triggers a cutaneous inflammatory response that involves the degranulation of mast cells. These neurogenic inflammatory reactions are physiologically similar to IgE-mediated hypersensitivity responses, which also depend on mast cells. Although non-antigenic stimuli distinguish neurogenic from IgE-mediated inflammation, the similarity of their effector stages suggested that peripheral nerves may also participate in lgE-mediated responses. To examine this hypothesis, IgE responses were elicited in denervated skin. A murine model was developed where the footpad was denervated by surgically removing a 2 mm segment of the sciatic nerve, proximal to the …

The Role Of Longshore Sediment Transport In The Loss Of Fill Material From An Estuarine Groin System, R. Neville Reynolds

OES Theses and Dissertations

The influence of shoreline structures on longshore sediment transport and the evolution of a stable beach planform was investigated at Willoughby Spit, Virginia following the placement of 410,590 cubic meters of beach fill within a groin system. Shoreline changes and wave conditions in a single groin compartment, and the growth rate of a downdrift terminal spit were monitored during 1985 and 1986. Short term fluctuations in the shoreline position within the groin compartment suggested an episodic westerly movement of sediment through the groin system. Primary sediment moving events were associated with northerly winds which produced waves up to 50 cm …

Interpreting The Personal Orientation Inventory Through The Five-Factor Model, Diane Donald Anderson

Psychology Theses & Dissertations

This study was designed to determine how the Personal Orientation Inventory (POI; Shostrom, 1974) relates to the Five-Factor Model of Personality. Four self-report personality instruments were employed; the Personal Orientation Inventory, the Comrey Personality Scales (CPS; Comrey, 1970), the NEO Five-Factor Inventory (NEO-FFI; Costa & NcCrae, 1988), and the Five-Factor Nodel Adjective Factors (AF,", Costa & NcCrae, 1985b). Data were collected from 128 psychology students aged 18 to 30 years. Scores for the Five Factors were obtained by factor analysis combining responses from the CPS, the NEO-FFI, and the AF. Pearson product-moment intercorrelations were then computed for the Five Factors …

The Study Of Oxygen Transport Through Polycrystalline, Single Crystal And Alloyed Silver, Dongchuan Wu

Physics Theses & Dissertations

The permeation of oxygen through large grain polycrystalline silver, through the (110), (111) and (100) single crystals of silver and through Ag0.05Zr alloy have been studied over the temperature range of 400 - 800 °C. In addition, studies were also conducted using glow discharge dissociation of the supply side ( upstream ) molecular oxygen in order to examine whether normal dissociative adsorption is a limiting step in the overall transport process.

The permeability of oxygen through polycrystalline silver was found to be quite linear and quite repeatable. The diffusivity measurements were found to exhibit two distinct linear regions, one above …

Microwell Based Solid Phase Competitive Enzyme Immunoassay For Estradiol And Estriol, Jeng-Ting Yang

Chemistry & Biochemistry Theses & Dissertations

A sensitive and simple microwell based competition enzyme immunoassay for the quantitative determination of estradiol (E₂) and estriol (E₃) was developed. Nicrowells coated with antibody were incubated with antigen followed by adding horseradish peroxidase (HRPO) conjugate. The assay, which can be performed within two hours at room temperature, involved simultaneous incubation of E₂ - or E₃-HRPO conjugate and serum sample in polystyrene microwells coated with anti- E₂ or anti-E₃ gamma globulin fraction.

Gamma globulin was isolated from whole anti-serum by DEAE-cellulose chromatography. A carbodiimide coupling method was utilized to prepare the …

Phytoplankton In Lake Drummond And Two Drainage Ditches In The Great Dismal Swamp, Virginia, Christine Gregory Phillips

Biological Sciences Theses & Dissertations

A twelve month study was conducted on the phytoplankton of Lake Drummond and Washington and Jericho Ditches from December 1988 to November 1989. Surface water samples were collected for nutrient and chlorophyll analysis from June 1989 to November 1989. The dominant phytoplankton component was the pico-nanoplankton (< 3 micron) category. A total of 57 species were identified from Lake Drummond, 51 species from Washington Ditch, and 31 species from the Jericho Ditch. Three major phytoplankton groups were identified at these sites: bacillariophyceans, cyanophyceans and cryptophyceans. The dominant species was the diatom Asterionella formosa. Nutrient and chlorophyll concentrations increased from summer to fall. Based on nutrient and chlorophyll g concentrations and species diversity indices, Lake Drummond is classified as eutrophic.

Investigation Of Mixing Characteristics Of A Lox Injector Operating At Non-Ideal Thermodynamic Conditions, W. Wei

Mechanical & Aerospace Engineering Theses & Dissertations

The mixing characteristic of a liquid oxygen (LOX) injector operating under nonideal thermodynamics conditions are analyzed. Oxygen, in supercritical state, is injected into a high pressure airstream flowing through a narrow annulus region of a hypersonic wind tunnel. The objective of the present study is to investigate conditions that would help produce a uniform profile of oxygen concentration at the end of a diverging mixing channel, located downstream of the injector section. Uniformity of oxygen concentration profile is critical to combustion processes that occur downstream of the LOX injector section.

The coupled velocity, temperature, oxygen concentration and enthalpy fields are …

Grid Generation And Flow Computation About A Martian Entry Vehicle, John Edward Stewart

Mechanical & Aerospace Engineering Theses & Dissertations

A number of vehicles are currently being proposed for a manned mission to Mars. One of these vehicles has a modified blunt-nosed cone configuration. Experimental results have been obtained for this vehicle in 1968. These results show lift-over-drag ratios comparable to those needed for Mars entry. Computations are performed here to verify the earlier results and to further describe the flight characteristics of this vehicle.

An analytical method is used to define the surface of this vehicle. A single-block volume grid is generated around the vehicle using an algebraic Two-Boundary Grid Generation algorithm (TBGG) and transfinite interpolation. Euler solutions are …

Encoding Phonetic Knowledge For Use In Hidden Markov Models Of Speech Recognition, Danming Qian

Electrical & Computer Engineering Theses & Dissertations

Hidden Markov models (HMM's) have achieved considerable success for isolated-word speaker-independent automatic speech recognition. However, the performance of an HMM algorithm is limited by its inability to discriminate between similar sounding words. The problem arises because all differences between speech patterns are treated as equally important. Thus the algorithm is particularly susceptible to confusions caused by phonetically-irrelevant differences. This thesis presents two types of preprocessing schemes as candidates for improving HMM performance. The aim is to maximize the differences between phonologically-distinct speech sounds while minimizing the effect of variations in phonologically-equivalent speech sounds. The preprocessors presented are a discrete cosine …

Finite Element Analysis Of Structures With Constrained Viscoelastic Layer Damping, Yung Chen

Mechanical & Aerospace Engineering Theses & Dissertations

It has been demonstrated that constrained viscoelastic layer damping treatments provide an effective means of passive control for structural vibration. These treatments dissipate vibrational energy by inducing shear strain in a thin layer of viscoelastic material. Our interest is in adding passive damping to a structure as an augmentation to active control. For such applications it is desirable to achieve high damping performance in a given frequency range with a minimum of added weight. Most damping treatments employ spatially continuous constraining layers over the entire viscoelastic layer. Plunkett and Lee have shown that the effectiveness of the damping treatment can …

Mathews County Shipbuilding Patterns, 1780-1860, Peter Jennings Wrike

History Theses & Dissertations

This thesis examines the volume and characteristics of a Chesapeake Bay county's shipbuilding activity to assess its impact on American waterborne commerce. The thesis proposes that this county built a significant number of fast sailing vessels in the late eighteenth and early nineteenth centuries. Previous works on American shipbuilding as well as regional histories have overlooked this county and concentrated on nearby large ports such as Norfolk and Baltimore. This thesis suggests these ports acted more as vessel brokers to the maritime industry than manufacturers and that this county was, among other small bay counties, a major contributor to that …

Use Of A Generalized Set Of Variables In Fluid Flow Calculations, Pawel Chwalowski

Mechanical & Aerospace Engineering Theses & Dissertations

In fluid flow calculations, a set of generalized field variables is used to replace the more conventional choice of either the conserved variables, or the primitive variables. This generalized set of variables represents an infinite number of possible choices for the specific set of field variables. For algorithms of both the implicit and explicit type, the resulting effect of a change in field variables on a steady-state flow solution is in general relatively small. However, for implicit algorithms, a consistent linearization with respect to the new variables results in dramatic changes in the overall matrix conditioning of the linear systems …

The Fokker-Planck And Related Equations In Theoretical Population Dynamics, George Derise

Mathematics & Statistics Theses & Dissertations

The population growth of a single species is modeled by a differential equation with initial condition(s) so that the number of organisms in the population is derived using some mechanism of growth, i.e. a growth rate function. However, such deterministic models are often highly unrealistic in population dynamics because population growth is basically a random event. There are a large number of chance factors influencing growth that might not be taken into account by deterministic models. The effect of other species (for example, in the chance meeting of a predator), population fluctuations due to weather changes that would alter food …

The Effect Of The Type Of Goal Setting Procedure Task Difficulty And Feedback On Psychomotor Performance, Jennifer Anne Mikulka Fletcher

Psychology Theses & Dissertations

The present experiment examined the effect of two levels of task difficulty (easy and difficult), two levels of feedback (feedback and no feedback), and three types of goal setting procedure (participative, assigned, and no goal setting) on performance. To control for effects due to goal difficulty, the assigned goals were yoked to the participative goals. A computerized letter cancellation task was employed to measure subject performance on three dependent variables: the number of correct. letter cancellations, the number of incorrect cancellations, and the reaction time between correct. cancellations ~ The results showed that the number of incorrect cancellations was not …